


Twins Are Dangerous: Short Stories

by theflyingpan



Series: Twins_Are_Dangerous_AU [4]
Category: Fire Emblem Series, Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Drabbles, Fluff, Funny, I hope, Major Spoilers, Minor Character Death, Minor Spoilers, Spoilers, Twins_Are_Dangerous AU, collection, head cannon stuff, sorta - Freeform, typical twin shenanigans
Language: English
Status: In-Progress
Published: 2019-09-26
Updated: 2019-10-02
Packaged: 2020-10-28 14:50:10
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 6
Words: 7,420
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20780378
Author URL: https://archiveofourown.org/users/theflyingpan/pseuds/theflyingpan
Summary: A collection of Short(maybe) stories in my Twins are Dangerous AU. Expanding the universe a bit and just writing about my head cannons. May contain spoilers, but I will give warnings before every chapter.





	1. Choosing a House Leader

**Author's Note:**

> Minor Spoilers about Byleth's mother

**Notes for the Chapter:**

> Minor spoilers for Byleth's mom, but nothing too revealing

Jeralt hadn’t expected his kids to fight, not after decades of silence and agreements between the two. They acted as if they were the same person: never disagreeing, always the same thoughts on their minds, never staying too far away from each other. After hearing stories from his men about fighting with their siblings over every little thing, Jeralt spent a good portion of the twins’ adolescence waiting in silent worry waiting for the moment the dam broke and the two started fighting like cats and dogs. The twins grew up, and that day never came— the only arguments the two had were minor and solved within a matter of minutes (nothing like the fights he was told to expect, the two only really argued about weapons or battle techniques). But as Jeralt settled into life back with the Knights of Seiros, the last thing he expected to have to handle was a full on fight between the two. Jeralt stared at his kids as they stood in his new office, settled down at his desk and watching the scene unfold for another few minutes.

“I. _Want_. The. Blue. Lions.” Byleth all but growled at his sister, frowning as she shook her head.

“You can lead the Golden Deer, didn’t you say that Claude ‘Seemed like more fun’?” She countered, her soft voice sounding much more cold than usual. Her brother curled in a bit more, hands shaking before curing into fists.

“And didn’t YOU say that Edelgard was ‘_A lovely woman who seems like a level headed tactician_’?” He countered, mocking her voice by raising his own, high pitched and slightly shrill. Jeralt had to stifle a laugh at that, his son defiantly inherited his own sense of humor. Byleth rolled her eyes, crossing her arms and frowning.

“I am sure that Felix will enjoy sweeping the floor with you during training, I however will actually be able to hold my own in a fight” She smiled, poking her brother’s chest next to the injury he received a few weeks ago when he failed to dodge a stray arrow in a skirmish. “I think that is _much_ more valuable to the Lions than your horrible impressions of me.” Jeralt sucked a breath at that, biting his lip. His daughter always managed to find out how to get under people’s skin and press the wrong buttons—just like her mother. He saw Byleth’s hand twitch towards his dagger, and that’s when he knew he had to step in.

“That’s **enough**!” He declared, slamming his hands on his table and standing to stare at the two. Byleth faltered under his hard stare and his hand slowly move away from his dagger, and his sister closed her mouth and silenced the next sharp comment she was planning to throw at him. He glanced between the two of them. Going back was a _mistake_, but Jeralt knew deep down that Rhea was right; the two need a chance to grow as people, not as weapons or fighters. They needed to know how to talk and debate with their words, not with their fists; and Jeralt needed to start steering them on that path. Thus, his next words had to be careful and considerate, but Jeralt was never one for words.

“Since you two won’t stop arguing, maybe _neither_ of you should teach the Blue Lion House.” He nearly spat out, sighing and rubbing a hand over his face. Being a father was tiring, and he had hoped that by now he would be able to stop lecturing the two. He hardly gave a lecture to the twins as kids, seeing how they learned through experience and not words, but there was always the rare cases where he needed to sit the two of them down and simply hoped his words didn’t go through one ear and out the other. He didn’t mean to sound so aggressive, but the stress was piling on; the knights, Alois, Lady Rhea and her schemes, Alois, Seteth and his cold words, **Alois**. He wanted to help the two talk things out, he really did, but the only one who was the talker in the family was buried deep underground— and Jeralt wasn’t ready to face that yet.

“Sorry Jeralt.” Jeralt peaked through his fingers, raising an eyebrow at the sound. The twins were staring at their feet, silent and shameful of their actions. Their voices had synced, and he heard the soft echo of her voice, as if calling for him from her grave. He smiled a bit and shook his head, he couldn’t stay mad.

“Well, how about this.” He walked over and clapped a hand over their shoulders, causing them to glance at him. “Byleth can have the Golden Deer, and Byleth can have the Black Eagles.” He smiled a bit and the two considered this outcome.

“Who will lead the Blue Lions then..?” His daughter wondered. Jeralt hummed at that.

“Well maybe _I_ can lead them, you two made it seem so easy to teach a bunch of noble brats.” He mused, smiling in amusement as the two started arguing again, this time directed at him.

**Notes for the Chapter:**

> Could you guys image Jeralt having to teach a house?? I can't choose who to feel sorry for, the students or him.


	2. Recruitment: Lorenz

**Summary for the Chapter:**

> Recruiting students is easy if you shower them with gifts and take them to tea over and over. Or just be the nicer twin.

**Notes for the Chapter:**

> No spoilers!

Byleth sighed as she tossed another half used bow aside. She continued to shift through the weapons in the convoy, slowly getting more and more frustrated. She and her class had just returned from a training battle, and despite breaking her bow halfway into the fight, Bernadetta was able to use the training spear Byleth gave her for “emergencies” surprisingly well, and was even named MVP of the battle. As Caspar and Dorothea had dragged the poor girl into a victory dinner, Byleth slipped away with the broken bow in hopes of repairing it. The smart thing to do would be to grab any other broken or nearly used weapons from the convoy and get them all repaired at once, so she did just that. However, due to sharing the convoy space with her brother, she was taking much longer than expected.

Byleth had a habit of using a weapon till it breaks, while her brother liked using weapons at no less than 70% durability; hence the half used bows and swords just haphazardly tossed into the convoy bin.

“Seriously…” She muttered as she found another half broken lance. While she had a habit of carrying broken weapons, she had never seen this many broken training lances in her life. Tossing the lance in the pile with seven others, she leaned over and continued to shift through the weapons. She knew exactly when he entered the room(perhaps it was due to the twin thing Claude mentioned a few days ago), so the weight against her back as her brother pressed his chest on her and leaned forward with her wasn’t surprising, and neither was the way he rested his chin on her shoulder and peered into the convoy with her. She glanced at his face and raised an eyebrow as she held up yet another lance. When he simply looked to the right, she frowned.

“Whose is this??” She pressed, gesturing to the rest of the lances and staring at him. A beat of silence passed before he turned back to the convoy and plucked a steel bow up, examining it with a blank stare.

“…Lorenz” He shrugged, and she frowned further.

“_All_ of them? They must have at least one use before breaking.” He said nothing, putting back the bow and plucking the lance from her hands.

"This has at least _two_ uses. He’ll be fine.” He moved to put it back into the convoy, but before he could his sister grabbed it from his hands.

“Do you enjoy teasing him like this?” She sighed and pushed herself away from the cart, effectively putting some distance between herself and her brother and allowing her to turn and stare into his eyes. His face was as blank as ever, but Byleth knew that the glint in his eyes confirmed her question. She stared back at him, the gears turning in her mind, and that’s how Claude found them.

“Hey Teach, er, teach-es!” He called out, walking into the training hall and waving at his two professors. They were having another one of their famous “twin contests”, as he called it, the two staring at each other in silent conversation. The male turned to face his student, nodding a bit to acknowledge him before turning back to his sister, who glanced at Claude. She smiled, something rare or the silent, more reserved twin—but as she walked past her brother Claude recognized the scheming look she wore, nearly identical to her brother’s. This was gonna be good.

“Hello Claude, how are you?” She asked, lacing her hands together behind her, the usual shyness long gone as she looked the young lord over.

“Ah I’m well! It’s unusual to see you so open Miss.” Claude smiled back, his hands also finding their way behind him as he rested his hands on his head. “Can I help you with anything?”. Byleth smiled a bit more, nodding her head slightly.

“Well, as a matter of fact, you _can_.” She turned and faced her brother, still standing by the convoy. “Care to tell me where _Lorenz_ is?” She asked Claude, and her brother froze as he bent over to reach for a discarded lance from the pile. Claude hummed a bit,

“I think I saw him in the Corridor earlier, need to speak to him?” Byleth smile widened as she stared at her brother.

“Yes, I wish to discuss some things with him. Thank you for the assistance.” She turned back to bow at Claude before walking past him. Claude bowed his head and walked to his house leader.

“What was that about teach?” Byleth had straightened up, holding a lance and staring after his sister. Claude recognized the look in his eyes, as Byleth turned the lance in his hands in thought. “She seemed a bit different, kinda like how you act when you come up with a good scheme to counter mine.” Claude leaned forward, ignoring Byleth’s personal boundaries as he also inspected the lance. “Is that the one you gave to Lorenz yesterday?” Byleth looked at the lance, before he finally connected the dots.

“Wait…”

“Ugh it took you long enough! I would’ve yelled at you sooner, but she used me to travel to the corridor as quickly as possible.” Sothis sighed as she re-appeared in his mind. “I’m not carrying _you_ over there though, so if you wish to keep your little punching bag, start running.” Sothis was barely done with her sentence before Byleth ran out the door full speed, chasing after his sister. Claude stared after his teacher, shocked, before shrugging and walked after him, albeit much slower. He got to the Corridor just in time to see Lorenz and the female Byleth shake hands and smile, as her brother leaned against a table panting. Both were too late to prevent Lorenz from switching houses and joining the Black Eagles.

Later that day Lorenz joined his new professor at the blacksmith and helped her repair and forge weapons for his new classmates. He didn’t complain a bit, perhaps due to the new steel lance he got as a reward. He also enjoyed the look on Claude's face when he announced his change in houses.

**Notes for the Chapter:**

> ((Ok maybe not all of them are going to be super long or anything))  
Male Twin Byleth would totally tease Lorenz and "forget" to repair his lances and stuff for battles; Female Twin Byleth likes to tease as well, but she teases her brother more than anyone else. Next up you'll see who Male Twin Byleth Recruits for his house, and after that more Jeralt shenanigans.


	3. Recruitment: Felix

**Summary for the Chapter:**

> Recruiting students is really easy if you shower them with gifts and take them to tea over and over. Or just promise to fight them

**Notes for the Chapter:**

> Minor spoilers for Felix and Dimitri supports? Maybe? (If you know the story, then you'll understand, if you don't know the story then you should be fine)(Nothing Major)

Felix sighed as he faced the training dummy once more. His hands shook, but not from exhaustion, but anger. He spent all morning in the training grounds, working on his sword technique— alone. He wanted to train with an actual person, such as Sylvain. Felix thought back to last night, were Sylvain kept him up all night ranting about his failed date and pressuring him to join him on his next night out and causing him to lose many precious hours of sleep—okay maybe _not_ Sylvain, but perhaps the boar would provide a good sparring partner. Felix then thought back to two days earlier, when the professor (female, it was always the female one) had walked into the grounds while Dimitri and Felix were practicing their lance techniques. Her entrance distracted Dimitri and Felix thought he had an easy opening, but Dimitri accidentally hit him in the face with his lance as Dimitri tossed the weapon aside to rush over to her side, hoping to provide any assistance she might need. Byleth was just looking for her brother, and neither Sylvain nor Claude could stop laughing when Felix stormed off to see Professor Manuela as Dimitri fussed over him like a mother hen and spilling apologies like water from his lips

Felix groaned and stabbed the dummy a bit too hard in frustration; _definitely_ not Dimitri.

“You missed” A voice called out, and Felix fought the urge to jump at the sudden sound. He whipped around and saw Byleth, standing a few feet behind him with a bank stare on his face. “Where were you aiming?” He pressed, walking forward and invading Felix's personal space. The sword was stuck in the dummy’s ‘chest’, and Felix ignored the question in favor of ripping the sword back violently. The professor hummed a bit and moved his gaze over Felix’s shoulder to stare at the dummy. “You and I know that a wound like that wouldn’t stop the more determined enemies” He commented, and Felix turned away, face turning red.

“Shut up” he muttered, twisting the blade in his hands. Byleth glanced over, face still expressionless as he stood straight and faced Felix. No sooner did Byleth move his hand towards his sword did Felix jump forward, bringing the sword from it’s resting position at his legs to swing upwards towards his teacher. Byleth smirked a bit, his own sword unsheathed and moved to counter Felix’s in a fast blur of movement.

“You’re getting faster” He commented, moving to push the young noble back a few feet before swinging again to counter another strike. Felix huffed in frustration, still not landing any blows on the skilled mercenary.

“Not fast enough” he groaned, his sword striking air once again. The professor chuckled a bit at this, striking Felix’s hand and forcing the student drop his sword in shock. “Ow hey!” Felix frowned and stepped back. “That was a low blow, don’t you think?” Byleth hummed, bending to pick the sword up.

“Dirty tricks or not, you do whatever you need in order to survive and win a battle” He lectured, and a thought crossed Felix’s mind at the words. Right as Byleth had a hand on the sword, Felix kicked his feet in the sand. “What the- hey!” Byleth’s grip slipped, and Felix took the opportunity to tackle the man into the ground. “Okay, _that_ was a low blow” The man groaned, rubbing the dirt from his eyes. Felix smirked, still pinning his teacher down in the dirt at his chest.

“But I won, didn’t I?” He mused, and he felt Byleth’s chest rumble with a short laugh. Byleth sat up, tossing Felix in the process and shook the dirt from his blue hair. He stood and helped Felix up, patting his back.

“Perhaps I need to be more ruthless with your training” He mused, and Felix couldn’t help but light up at the idea. Being able to fight his professor with no regard of nobility or pride, _that_ would be interesting. Felix then thought of a battle similar to the one he imagined, with blood dying blonde hair a sickening red and a sharp laughter ripping through the sky.

“Maybe I should beat some _pride_ into your work” Felix countered, raising an eyebrow as he eyed the mercenary. Byleth smirked a bit, holding out a scroll. Felix cautiously took the paper, reading it and recognizing it as the document necessary to allow him to change his house.

“Filling that out will help give me more time to dedicate to you specifically, you know” Byleth explained, sheathing his sword and picking up the one Felix used, also handing it over. Felix turned the sword over in his hands, weighing his options. On one hand, he would be leaving the boar’s side, unable to watch him as closely for the day he broke and starting going feral. On the other hand…the battle of the Eagle and Lion was approaching, and switching classes would mean an opportunity to absolutely thrash Sylvain in front of the whole school.

“I’ll consider switching” Felix muttered, and with the way Byleth rolled his eyes and nodded made him think that his professor somehow knew his decision was already made. 

* * *

“Oh, just as a precaution” Byleth started, stopping before he and Felix exited the training grounds. “Don’t use those tricks against my sister” Felix rolled his eyes.

“Let me guess, you don’t want your _precious_ little sister being made a fool of with low blows and dirty tricks.” he sighed, a bit surprised as Byleth shook his head and shuddered, a dark look crossing his face.

“No, if you do that, she’ll _absolutely_ trash you.” Felix raised an eyebrow. His professor had a distant look on his face, as if recalling a moment from the past. “I tried throwing sand in her eyes in order to distract her and win a training session years ago” he lowered his voice and suppressed a shudder. “She got so upset that it took five men from Jeralt’s group to hold her down and prevent her from taking my eyes as punishment” Felix, for all his grumpy attitude and apathetic nature, couldn’t stop the laughter that escaped his lips.

**Notes for the Chapter:**

> God I hope this isn't OOC I haven't interacted with Felix nearly enough to write this
> 
> Male Twin Byleth made the mistake of fighting dirty with his sister years ago, he won't let his student make it too (AKA play fair with Female Twin Byleth or your eyeballs are in danger). I like to think that recruiting Felix is as easy as "Come to my class we can fight each AND Sylvain" (also if you squint you can see some Felix/Sylvain content, but you have to squint pretty hard and get kinda close to the screen)


	4. Names

**Summary for the Chapter:**

> Jeralt is still bad at names, but he makes it work.

**Notes for the Chapter:**

> No spoilers! Yay!

“Jeralt, sir?” A female voice called out, and Jeralt turned away from his kids, halting his lecture about weapon repairs to find the source. Edelgard stood near the entrance of the Training Hall with the other two nobles at her sides. Jeralt excused himself and walked over, already surpassing a sigh. The twins turned to face the task he gave them, repairing a bow with the new tools they were provided.

“Can I help you, _crown princess_?” He asked, trying not to sound sarcastic. Edelgard blushed a bit at the title, looking away as Claude coughed and stepped up.

“Yeah, just got a few questions about the teach! Care to help enlighten us?” He asked, and Jeralt decided to ignore the glint in his eyes.

“Can’t you ask them?” This time, Dimitri spoke up.

“Well, with all due respect sir, this is something they cannot answer for us. Only you can help us.” Dimitri’s face stayed determined all throughout the comment, and Jeralt raised an eyebrow.

“Alright, I’ll bite. What is it?” He eventually sighed and asked, crossing his arms. The three shared a look before Edelgard spoke up again.

“Why did you name them the same name? It makes it hard to talk with them” Jeralt tried not to roll his eyes—he heard this question nearly every day of his life. Seemed like everyone had an opinion about his choice, and some more options to rename the two whenever he wanted to (no, he would not name his son ‘Jeralt Jr.’; yes ‘Fodlan’ was an _awful_ name for a child; no his daughter will not be named after Lady Rhea and _how dare they even suggest that_).

“Not to say that their name is a bad name!” Dimitri stepped forward, afraid of insulting the man. Jeralt decided rolled his eyes at that. “Byleth is a good name, I think it sounds very elegant!” Claude elbowed the Prince before he could continue to embarrass himself further.

“We mean,” Claude sighed “to ask how you manage to get one of their attention without alerting and summoning the other” he smiled sheepishly. “It’s frustrating to call for the male and have the female walk over and try to answer the question” Ah, _there_ it is. Jeralt was waiting for the moment when the nobles will stop dancing around the problem and just outright ask him, it tended to happen a lot with noble folk. Jeralt spared a glance at his kids, turning the thought in his mind. Byleth had managed to fix her bow with the new tools the monastery provided, while her brother had given up and started to polish the lances and swords.

“I’ll demonstrate, if you could help me” He responded and turned back to Edelgard, holding out a hand. “May I borrow a ribbon?” She looked confused, but relented— untying a hair ribbon and handing it over. He nodded before turning back to face his twins. “**Byleth**” He called out, his voice steady and low. His son turned to face him, and walked over when Jeralt said nothing more. His sister continued to work, her back to the nobles and not even batting an eye as Jeralt summoned her brother over. Byleth glanced between the nobles and his father, looking slightly confused but still holding his classic stoic expression. Jeralt held out the ribbon and dropped it in his son’s hand. “Go try and tie this into your sister’s hair. It should be easy, like _restringing a bow_.” His son frowned a bit, glancing back at the discarded bow before nodding and walking back to his sister. Jeralt smiled as he struggled to tie the ribbon in Byleth’s long and messy hair before turning back to the nobles. Edelgard was still a bit red, and Claude was smiling like a fox.

“_Wow~_” He whistled. “How’d you manage to get just one?” Claude pressed, but Jeralt shook his head and held up a finger, turning to face the twins again.

“_Byleth_,” He called again, this time raising his voice and using a softer tone. His daughter turned and walked over this time, the ribbon barely hanging onto a strand in her hair. Her brother had turned back to the discarded bow, learning his lesson. Jeralt smiled, and looked back at his daughter, her head tilted at him and an eyebrow raised. He took the ribbon back out and sighed. “He couldn’t even manage this?” She shrugged, taking the ribbon back and walking to Edelgard. After a silent question, Byleth focused on retying the ribbon back into the Princess’ hair. Satisfied with her work, Byleth walked back to join her brother. Jeralt smiled and turned to the nobles.

Edelgard was as red as her house flag, Dimitri was just as shocked, and even Claude’s signature smile was long gone, replaced with confusion.

“It’s all about your tone” Jeralt explained, winking before leaving the stunned nobles at the door. His satisfaction was short lived, however, as the three took turns practicing calling his kids’ name over and over for the next two weeks(some of the other, more bolder, students joined in as well, and he swore he heard a few knights practice when they thought he wasn't around). By the time that the twins confronted him for an explanation, the house leaders were able to successfully call their professor’s name and get the right one’s attention. Not that it mattered much, but it certainly helped the twins ease into life at the Monastery.

**Notes for the Chapter:**

> Random thought I had, how would Jeralt get just one of the twin's attention? I imagine that, before they had this system, he would just call out their names and stare down the one he wanted to talk to until they got closer so he can speak to them. I also imagine that they just stared back until he got tired and just pointed to the one he needs to speak to.


	5. Lady Rhea

**Summary for the Chapter:**

> Rhea finally has some time for herself, which is dangerous when her memories enjoy haunting her.

**Notes for the Chapter:**

> MAJOR SPOILERS: uh for Rhea's Past and Byleth's birth?  
Also this is wildly inaccurate (probably) cause everything I know about that topic is based on other fan fictions lol

Jeralt didn’t like Rhea, didn’t trust her, didn’t want his kids near her. And Jeralt wasn’t one to hide his feelings, so he expressed his thoughts to his kids as well. Byleth took his advice to heart, distrusting Rhea the moment he laid his eyes on her. His sister was more hesitant, Rhea’s soft voice and smile conflicting the image Jeralt painted of her.

But as the weeks rolled into months, and the twins received more missions from the Archbishop, Byleth noticed something about that soft and sweet smile; she was never the one they were directed towards. Whenever they had to speak to the Archbishop, her brother made her talk to the woman (“You can fake sincerity better than I can” he had claimed, and resolved to stay silent in their meetings lest his bitterness slip out), and Byleth saw the way Rhea regarded her. While she received a thin smile and short, curt replies to her questions; her brother was the receiver of the soft and kind smiles, the gentle voice and pleasant conversations. In fact, if Byleth was better suited to reading a room, she would even say that the Archbishop _preferred_ her brother over her— but she never thought that despite it being the truth. Lady Rhea gave the male twin more urgent missions and asked him for more quests, while the female twin was often given missions and quests from Seteth.

Byleth didn’t really mind; it gave her brother some time to adjust his face and emotions to appear more stoic around the Archbishop, and it gave herself some time to get to know Seteth as well as Flayn (who always seemed to pop in during their meetings and invite herself to some tea). But there was something about the way Lady Rhea looked at her, with a slight frown and distant eyes, that rubbed Byleth the wrong way— especially when Rhea would turn and smile at her brother as if he was a _god_ of sorts. Not to say she was jealous— Byleth knew what jealousy was, that was _not_ what she felt— but a pit always formed in her stomach and Sothis always seemed to press for the two to leave when it happened (It seems like Sothis disliked Rhea’s smiling face she reserved for the male twin more than the cold and calculating face she used for the female). No matter how long she spent at night, staring at the ceiling and talking to Sothis, Byleth couldn’t figure out why Rhea seemed to hate her.

“Maybe she doesn’t hate you” Sothis commented, lying between the twins one night as her brother snored sound asleep. “She doesn’t look at you with hatred or anger you know.” Byleth hummed a bit at that, her voice awfully loud in the quiet of the room.

“…she looks sad sometimes” She realized, and Sothis nodded solemnly.

“Maybe you remind her of someone she lost, or something she cannot have?” Sothis yawned, pressing her back against the male twin and getting cozy. “Well, it’s not like you have done anything to warrant her hating you, you barely know her.” Sothis was silent after that, falling asleep and slowly fading from Byleth’s view. She stared at the empty spot, her brother’s back rising and falling with his soft breaths. She thought of her time at the monastery and came to the same conclusion as Sothis: She didn’t do anything that would make the Archbishop act so cold to her, at least, not when she was a professor at least. Byleth settled down for sleep, pressing her face against her brother for stability, drifting off to join him in an ancient throne room with the girl with braids and green hair, her worries suddenly gone.

* * *

Rhea sighed as she took off the heavy headpiece, safely tucking it away in her room before sitting on her bed to untie her hair. She had an exhausting day, and she blamed it all on the month’s mission. This month she wanted the three houses to help provide more protection for the upcoming ceremony, a heavy task with large responsibility. Thus, it was up to her to address the new professors and give them their assignment. Rhea’s hands faltered a bit as she thought back to the meeting, pausing in their task. Byleth was staring her down, his distrust still swimming behind his _beautiful_ eyes and cold expression. She was slowly learning to read his face and movements, and she would never tire of seeing his face light up when she gave him the month’s mission— watching the way he turned the idea over in his head and start forming battle tactics and lesson plans right there on the spot. She was _proud_ of him, as proud as she was allowed to be after all.

But his sister… Rhea frowned and lied back on her bed, gently pressing a hand over her beating heart. She closed her eyes, and allowed herself to have this private moment. She heard the echoes of her own voice, crying out in fear, and allowed herself to fall into the memory.

...

Rhea held the child in her arms, the boy lying silent and still. She knew from the subtle rise and fall of his small chest that he was alive, but the shallow breaths worried her some. Rhea smiled at him, and turned to face her dear friend to give her the news, that her new son will be safe, that Rhea will _never_ stop trying to keep him alive. Her face fell. Why was she still heaving heavy breaths? Why was she still in pain? Rhea herself held her only child in her arms, so _why was she still pushing?_

Rhea stood stock still as the nuns rushed around her, panicking to help deliver and save the second child—the child that no one expected<strike>(that no-one wanted)</strike>. With a final push, her best friend in the world breathed her last breath, and a sharp cry rang out in the room. Rhea nearly jumped back at the sound, bringing the infant boy closer to her chest in protection. A nun turned to face her, a small weak smile on her face as she presented a baby girl to the archbishop. The girl in her arms wiggled a bit and whined, a stark contrast to her brother who was dead silent in Rhea’s arms. The nun frowned a bit and brought the girl back to her body, but Rhea’s eyes had already moved to look past her, to the corpse of her friend. The boy in her arms stopped moving, but that didn’t matter. She _will_ save her friend’s son.

Rhea spared a glance at the girl, the one who killed her friend,<strike> the one no-one needed.</strike> The girl was breathing strangely as well, a fever perhaps. She opened her eyes just enough for Rhea to see familiar blue eyes, and that ghost the kind shine that used accompanied them haunted her.

Rhea took the girl from the nun quickly, to avoid seeing those piercing eyes again. She stormed out of the delivery room, retreating through a side door to a small operating room. She placed the twins beside each other— the boy’s body long gone cold in her arms, the girl’s body dangerously warm. Rhea stared at them, before closing her eyes and recalling the image of their mother. She will save them. If anything, at least just one.

...

Rhea sighed and opened her eyes again, dragging her mind back to the present. She sat up on her bed again, moving to stare at her hands. The infant blood that had stained her fingers were long gone, but sometimes she saw flashes of it. She saved Byleth with all of her might, implanting a crest stone where his heart should be. His sister _should’ve_ died from the fever—Rhea almost wanted her to. It was easier than seeing the familiar face grow up and haunt her in her every waking moment. But despite everything, she also survived that night. Rhea had no idea how, especially when Professor Hanneman asked her why _both_ twins had the long lost Crest of Flames when they returned to her just a few months ago.

Before Jeralt burned his way out of the Monastery, Rhea had snuck in and gently rested her ear over each infant’s chest. The boy’s silence comforted her—knowing that the crest stone gave him the energy to live and breathe—but the silence from the girl worried her. She didn’t plant anything in her heart, she only had one stone, and she hardly had time to treat the fever she was born with; so why did she live? What happened?

Rhea in the present shook her head, and continued to prepare for bed. Another mystery for another day, and there wasn’t a day that Rhea didn’t turn the thought in her mind, or experience a strange fear when she looked at the girl.

Not only did she have more similarities with her dead friend than the male did, but she also had the added weight of being alive when she should’ve died decades ago.

**Notes for the Chapter:**

> Yeah...I had some thoughts for the twin AU but uh...I didn't get to that part in the actual game so this is totally not accurate.  
Anyway, Rhea has some issues with female Byleth, and entirely different issues with male Byleth. Also I'll probably explain what this all means for female Byleth in another chapter/story.


	6. Faking It

**Summary for the Chapter:**

> Jeralt notices something strange about the Professor in charge of the Golden Deer house one morning. He decides to investigate.

**Notes for the Chapter:**

> No spoilers! Decided to post this along with the previous chapter so the people who skipped that one could at least read something.

The Byleth twins got sick one (1) time. Jeralt remembered it clearly. The fear he experienced when he saw his two kids collapsed on each other in an unfamiliar inn after a long trek to a small town was something he hoped he would never experience again. The horrible, deadly disease that his poor poor kids have caught was deemed “a harmless cold” by a kind innkeeper, and the two slept for nearly a week to recover while he was stuck worrying over them. After leaving the town, the twins as healthy as before, Jeralt had sighed and hugged them tight.

“For the love of the goddess, please don’t ever scare me like that again” he begged them. They shared a look over his shoulders before he felt two pairs of small hands reach around him grab his coat.

“Sorry Jeralt” They said in unison, sounding a bit worried. He had sighed and shook his head, smiling. The three set off, leading their group to another mission in another town.

That was years ago, nearly a decade if Jeralt had bothered to count, and the two never got sick again. He wasn’t sure if it was because they were more careful to dress appropriately and clean themselves, or if they just made a bold resolve to never get sick again and their combined willpower made that possible, but the two never came down with another sickness again. There was, of course, some consequences to this. Byleth sometimes got super nauseous along with sharp abdominal pains during the end weeks of the month for years, and she sometimes just laid on her side in the middle of training and stayed still, fighting away the urge to empty her stomach. Her brother on the other hand sometimes got violent and painful migraines, sometimes standing very still as the world around him spun—even if they were in the middle of a battle. Jeralt worried more for the two due to this, but his men just chalked it up to ‘weird twins being weird’. Jeralt soon adopted the same attitude, and after arriving to Garrac Mach he forgot that the consequences might seem strange to others. But that didn’t matter, the twins still taught their classes and trained with their students, and if anyone noticed the way their female professor sometimes laid in the grass for nearly an hour, eyes closed and cats surrounding her, or the fact that their male professor sometimes froze during his training exercises or lectures, eyes unblinking and hand shaking slightly, they never mentioned it.

All things considered, Jeralt didn’t bat an eye when he saw his son walk into the cafeteria, nodding to Dimitri with a gentle smile as he got a plate of fruits for breakfast, walking along the wall to sit at the table with Raphael and Igna—

_That wasn’t his son_, Jeralt realized suddenly, dropping his spoon back onto his plate in surprise. He leaned forward and tried to concentrate on the figure wearing his son’s clothes from his position two tables away sitting between Alois and Catherine (who were making it very hard with their current argument). The figure had the same blue hair, but it was slightly longer. The same eyes, but a more rounder shape.

Jeralt sighed and stood up, walking over to the table and sitting next to the figure. Ignatz yelped a bit at the knight’s sudden entrance, giving a stuttering greeting, while Raphael greeted him with a mouthful of food. The figure stiffened a bit, and gave a stiff nod in acknowledgement. He smiled at the students, and leaned over to whisper in the figure’s ear.

“Wanna tell me how you suddenly became the leading professor for the Golden Deer house?” He asked his daughter, who bit the peach on her fork a bit too aggressively. Jeralt smiled a bit and leaned his head on his face, watching his daughter struggle to answer him.

“…I…have no idea what you’re talking about…” His daughter coughed out, voice a bit deeper than usual. While that might’ve fooled Ignatz and Raphael (which may be the reason his daughter choose to sit with them, Jeralt realized with a hint of pride, good thinking), Jeralt could easily see through the fake voice.

“It’s nice to finally see you eat some good food for a change, _son_” Jeralt hummed, plucking a plum from his daughter’s plate and ate it, side eyeing her to gauge her reaction. She glanced quickly at him before nodding a bit, ignoring his comment and turning to face the two students in front of them. Jeralt hummed and gazed at Ignatz as he started a conversation about his next bow training session. The kid seemed to really look forward to it, and to her credit, Byleth did give input when needed, giving him some initial tips for him to start thinking about. The plates at the table were soon empty, and as Raphael stood to attempt to get a third serving, Byleth stood and attempted to escape before anyone else saw through her disguise.

“Hey teach! Wait up!” Jeralt suppressed a laugh as Claude ran over to his daughter, preventing her from escaping. This was going to be good, so he stood and walked over casually, picking his abandoned plate up from between Alois and Catherine and returning it so he could hear the disaster that was about to take place.

“So I was thinking that maybe you could sweet talk Hanneman and we can have a little mock battle with those blue lions over there,” Claude was saying, Jeralt only catching the tail end of the conversation. He leaned against the food counter next to Raphael, who was waiting for his plate to return, and smiled at his daughter. Byleth gave a weak smile and nodded at the student in front of her, ignoring her father’s knowing smile.

“Y-es! That sounds like, a good idea. Maybe you could, well, get some good practice, um, with defending in the air…” Byleth mumbled, attempting to hide the different tone with a fake yawn. Claude cocked his head to the side, putting a hand on his hip and eyed the professor in front of him. Jeralt saw the way his daughter’s eye flicker to the side quickly and smirked a bit.

“Hello Mr. Jeralt!” Leonie walked over and greeted him. Jeralt kept his eyes on his daughter but nodded. “What are you doing today?”

“Watching a disaster unfold” He replied, earning a confused look from Leonie.

“Geez Teach, you really are hard to talk to in the morning” Claude smiled, laughing. Byleth nearly sighed in relief, chucking a bit sheepishly. “Anyway, where’s the professor? She usually doesn’t skip breakfast.” Jeralt smiled, wondering if she would manage to get herself out of this one. Leonie had joined him, leaning against the counter with him and also looking over at Byleth (although Jeralt doubted that she understood what was going on). Byleth shrugged in response to Claude’s question.

“She wasn’t in our room when I woke up” She said calmly, and Jeralt wondered if she had prepared a response for that. “I think she woke up early to talk with Edelgard or something” Claude nodded at that, glancing over Byleth’s shoulder.

“Oh I guess so, there she is now.” Jeralt couldn’t suppress the sharp laugh that escaped his lips as Byleth whirled around, watching Edelgard walked into the dining hall with Hubert. Leonie gave him another look but Jeralt shook his head in response, watching his daughter relax a bit and turning back to face Claude.

“Yes, well, I suppose I should go find her then. Her...meeting seems to have concluded...” She mumbled and nodded to Claude before briskly walking out of the cafeteria, leaving a confused Claude in her wake.

* * *

Byleth sighed in relief as she closed the door to her room behind her, shrugging off the large coat and quickly snapping off the armor that was a size too big for her body.

“I am _never_ doing that again, understood??” She got a pained groan in response, and she threw her brother’s coat at him, nailing him in the face from his position in the bed. She walked over to him and sighed, glancing at Sothis as she floated beside her. She shrugged in response.

“He hasn’t gotten better you know” Byleth swatted at the green haired girl in protest, and his sister sighed and continued to take off her brother’s armor. She changed into her own clothes, feeling more comfortable with the lack of heavy armor and the breeze at her middle. Byleth sat up a bit in bed, trying to ignore the spinning feeling he felt. He eyed the two girls standing in front of him and noted the way they both looked at him in a judging manner.

“…what…” Sothis groaned and rolled her eyes, floating behind his sister.

“You need to get up, now.” His sister sighed and pulled on his blankets, earning another groan of protest. He ripped the blankets from her hands and rolled over in bed, causing Sothis to roll her eyes.

“He won’t move, I would just cancel his classes” Byleth shook his head.

“No…don’t…Jeralt will get mad…” Sothis laughed.

“Well I wouldn’t blame him, you’re the one who challenged Shamir into a drinking contest and ended up black out drunk. Did you see Shamir today?” Sothis turned to the female, fully clothed and sitting at the desk reviewing her brother’s notes for class. She shook her head.

“She wasn’t in the cafeteria either, but Seteth did mention she had a mission today.” Byleth gave her a look.

“You think she went to work after that? She was just as drunk as me” His sister gave him a blank stare over his notes.

“She’s more experienced with alcohol than _you_ are” She sighed and stood. “I’m _not_ wearing your armor again, I don’t like the way it constricts me.” Sothis sat next to Byleth and watched his sister walk to the door. “You also need to talk to Hanneman about having a team training session with the Blue Lions. I’ll ask him for you but I am not covering for you anymore, this morning was stressful enough.” Byleth sighed and finally sat up, nodding in understanding.

“…fair enough…” Byleth sighed in relief and opened their door, ready to start greeting her own students, but came face to face with Jeralt, two seconds away from knocking on their door. His surprised face soon melted into a knowing smile.

“Oh hello Byleth, nice to see _you_ this morning. You missed breakfast.” Byleth stumbled out of bed, reaching for his discarded armor and ignoring the way the room spun around. His sister leaned against the doorframe, attempting to use her oversized coat to hide her brother’s movement. Jeralt crossed his arms and smiled, watching his daughter attempt to lie her way out of this one. Byleth was looking at a spot behind him, but when she did meet his eyes she felt herself crumble a bit.

“…Byleth had a drinking competition with Shamir…” She sighed, standing straight and moving out of her dad’s way.

“**OI**!” Her brother yelped in protest, but Jeralt just laughed as he walked into the room. Byleth was halfway into his armor, hair a mess and face a bit green from the sudden movements. He glared at his sister for cracking under pressure, but a hard stare from his dad shut up any other accusations. Jeralt sighed and sat on his kids’ bed, waving his hand at his son and urging him to continue getting dressed. He relented, putting on the rest of his armor and grimacing a bit as he felt the sweat.

“So…did you win?” Sothis laughed at Jeralt’s question, the sharp sound ringing in Byleth’s ears and making him groan. His sister giggled and sat next to her dad, feeling a bit better after confessing. Byleth sighed and snapped on the rest of his armor.

“…No…I think she won…” He decided to ignore the three voices laughing at him, and decided to empty his stomach on his sister the next time he got drunk as payback.

Not that he would be stupid enough to challenge Shamir to a drinking contest again.

**Notes for the Chapter:**

> Yeah Male Byleth has big dumb younger sibling energy (even though he was born first). Jeralt has fun teasing his kids.  
(Also yeah, poor female Byleth has really bad sickness when she's on her period)(and male Byleth gets really bad migraines sometimes but at least that gets better with time)


End file.
